However, three times more money was spent treating drug abuse than alcohol-related problems – health boards and councils spent £77m on drug services in 2007/08 compared to £26m for alcohol services.

Drugs and alcohol deaths are among the highest in Europe in Scotland with 4.9% of Scottish adults dependent on alcohol and 1.8% using drugs such as heroin.

The Audit Scotland report wants better coordination between agencies and clearer assessment of the impact of service to ensure value for money.

The cost to society, taking into account crime, work absenteeism and hospital treatment, is put as £2.6bn for drugs and £2.25bn for alcohol.

The report said: "Drug and alcohol-related death rates are among the highest in Europe and have doubled in 15 years. This is at a time when indicators of drug and alcohol-related harm are reducing in other countries in Europe."

Health Secretary Nicola Sturgeon said the government had been addressing this "historical imbalance".

"We've taken the decision to increase spending on drugs services by 14% over the spending review period," she said. "But the increase in spending on alcohol services is 230% because we recognise that historically there has been an imbalance in the spend between alcohol and drug services."